I notice a lot of people have a hard time admitting when something isn't working.
They'll pretend it does work.
They'll redefine what "works" means to them-- in a way that often goes against how they originally defined it.
They'll ignore the failure as long as they don't have to change what they are doing.
It's probably smarter to stop as soon as you notice something isn't working, or if you feel the desire to redefine "works" in the situation. Think about how else you might approach the problem. Try something else. Don't keep doing what you've been doing just because it's what you've always done.
And, even if it does work, there's probably a better way just waiting for you to discover it. See if you can.